forked from DFHack/dfhack
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Lua API.html
3395 lines (3314 loc) · 182 KB
/
Lua API.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="generator" content="Docutils 0.11: http://docutils.sourceforge.net/" />
<title>DFHack Lua API</title>
<style type="text/css">
/*
:Author: David Goodger ([email protected])
:Id: $Id: html4css1.css 7614 2013-02-21 15:55:51Z milde $
:Copyright: This stylesheet has been placed in the public domain.
Default cascading style sheet for the HTML output of Docutils.
See http://docutils.sf.net/docs/howto/html-stylesheets.html for how to
customize this style sheet.
*/
/* used to remove borders from tables and images */
.borderless, table.borderless td, table.borderless th {
border: 0 }
table.borderless td, table.borderless th {
/* Override padding for "table.docutils td" with "! important".
The right padding separates the table cells. */
padding: 0 0.5em 0 0 ! important }
.first {
/* Override more specific margin styles with "! important". */
margin-top: 0 ! important }
.last, .with-subtitle {
margin-bottom: 0 ! important }
.hidden {
display: none }
a.toc-backref {
text-decoration: none ;
color: black }
blockquote.epigraph {
margin: 2em 5em ; }
dl.docutils dd {
margin-bottom: 0.5em }
object[type="image/svg+xml"], object[type="application/x-shockwave-flash"] {
overflow: hidden;
}
/* Uncomment (and remove this text!) to get bold-faced definition list terms
dl.docutils dt {
font-weight: bold }
*/
div.abstract {
margin: 2em 5em }
div.abstract p.topic-title {
font-weight: bold ;
text-align: center }
div.admonition, div.attention, div.caution, div.danger, div.error,
div.hint, div.important, div.note, div.tip, div.warning {
margin: 2em ;
border: medium outset ;
padding: 1em }
div.admonition p.admonition-title, div.hint p.admonition-title,
div.important p.admonition-title, div.note p.admonition-title,
div.tip p.admonition-title {
font-weight: bold ;
font-family: sans-serif }
div.attention p.admonition-title, div.caution p.admonition-title,
div.danger p.admonition-title, div.error p.admonition-title,
div.warning p.admonition-title, .code .error {
color: red ;
font-weight: bold ;
font-family: sans-serif }
/* Uncomment (and remove this text!) to get reduced vertical space in
compound paragraphs.
div.compound .compound-first, div.compound .compound-middle {
margin-bottom: 0.5em }
div.compound .compound-last, div.compound .compound-middle {
margin-top: 0.5em }
*/
div.dedication {
margin: 2em 5em ;
text-align: center ;
font-style: italic }
div.dedication p.topic-title {
font-weight: bold ;
font-style: normal }
div.figure {
margin-left: 2em ;
margin-right: 2em }
div.footer, div.header {
clear: both;
font-size: smaller }
div.line-block {
display: block ;
margin-top: 1em ;
margin-bottom: 1em }
div.line-block div.line-block {
margin-top: 0 ;
margin-bottom: 0 ;
margin-left: 1.5em }
div.sidebar {
margin: 0 0 0.5em 1em ;
border: medium outset ;
padding: 1em ;
background-color: #ffffee ;
width: 40% ;
float: right ;
clear: right }
div.sidebar p.rubric {
font-family: sans-serif ;
font-size: medium }
div.system-messages {
margin: 5em }
div.system-messages h1 {
color: red }
div.system-message {
border: medium outset ;
padding: 1em }
div.system-message p.system-message-title {
color: red ;
font-weight: bold }
div.topic {
margin: 2em }
h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
margin-top: 0.4em }
h1.title {
text-align: center }
h2.subtitle {
text-align: center }
hr.docutils {
width: 75% }
img.align-left, .figure.align-left, object.align-left {
clear: left ;
float: left ;
margin-right: 1em }
img.align-right, .figure.align-right, object.align-right {
clear: right ;
float: right ;
margin-left: 1em }
img.align-center, .figure.align-center, object.align-center {
display: block;
margin-left: auto;
margin-right: auto;
}
.align-left {
text-align: left }
.align-center {
clear: both ;
text-align: center }
.align-right {
text-align: right }
/* reset inner alignment in figures */
div.align-right {
text-align: inherit }
/* div.align-center * { */
/* text-align: left } */
ol.simple, ul.simple {
margin-bottom: 1em }
ol.arabic {
list-style: decimal }
ol.loweralpha {
list-style: lower-alpha }
ol.upperalpha {
list-style: upper-alpha }
ol.lowerroman {
list-style: lower-roman }
ol.upperroman {
list-style: upper-roman }
p.attribution {
text-align: right ;
margin-left: 50% }
p.caption {
font-style: italic }
p.credits {
font-style: italic ;
font-size: smaller }
p.label {
white-space: nowrap }
p.rubric {
font-weight: bold ;
font-size: larger ;
color: maroon ;
text-align: center }
p.sidebar-title {
font-family: sans-serif ;
font-weight: bold ;
font-size: larger }
p.sidebar-subtitle {
font-family: sans-serif ;
font-weight: bold }
p.topic-title {
font-weight: bold }
pre.address {
margin-bottom: 0 ;
margin-top: 0 ;
font: inherit }
pre.literal-block, pre.doctest-block, pre.math, pre.code {
margin-left: 2em ;
margin-right: 2em }
pre.code .ln { color: grey; } /* line numbers */
pre.code, code { background-color: #eeeeee }
pre.code .comment, code .comment { color: #5C6576 }
pre.code .keyword, code .keyword { color: #3B0D06; font-weight: bold }
pre.code .literal.string, code .literal.string { color: #0C5404 }
pre.code .name.builtin, code .name.builtin { color: #352B84 }
pre.code .deleted, code .deleted { background-color: #DEB0A1}
pre.code .inserted, code .inserted { background-color: #A3D289}
span.classifier {
font-family: sans-serif ;
font-style: oblique }
span.classifier-delimiter {
font-family: sans-serif ;
font-weight: bold }
span.interpreted {
font-family: sans-serif }
span.option {
white-space: nowrap }
span.pre {
white-space: pre }
span.problematic {
color: red }
span.section-subtitle {
/* font-size relative to parent (h1..h6 element) */
font-size: 80% }
table.citation {
border-left: solid 1px gray;
margin-left: 1px }
table.docinfo {
margin: 2em 4em }
table.docutils {
margin-top: 0.5em ;
margin-bottom: 0.5em }
table.footnote {
border-left: solid 1px black;
margin-left: 1px }
table.docutils td, table.docutils th,
table.docinfo td, table.docinfo th {
padding-left: 0.5em ;
padding-right: 0.5em ;
vertical-align: top }
table.docutils th.field-name, table.docinfo th.docinfo-name {
font-weight: bold ;
text-align: left ;
white-space: nowrap ;
padding-left: 0 }
/* "booktabs" style (no vertical lines) */
table.docutils.booktabs {
border: 0px;
border-top: 2px solid;
border-bottom: 2px solid;
border-collapse: collapse;
}
table.docutils.booktabs * {
border: 0px;
}
table.docutils.booktabs th {
border-bottom: thin solid;
text-align: left;
}
h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
font-size: 100% }
ul.auto-toc {
list-style-type: none }
</style>
</head>
<body>
<div class="document" id="dfhack-lua-api">
<h1 class="title">DFHack Lua API</h1>
<div class="contents topic" id="contents">
<p class="topic-title first">Contents</p>
<ul class="simple">
<li><a class="reference internal" href="#df-data-structure-wrapper" id="id3">DF data structure wrapper</a><ul>
<li><a class="reference internal" href="#typed-object-references" id="id4">Typed object references</a><ul>
<li><a class="reference internal" href="#primitive-references" id="id5">Primitive references</a></li>
<li><a class="reference internal" href="#struct-references" id="id6">Struct references</a></li>
<li><a class="reference internal" href="#container-references" id="id7">Container references</a></li>
<li><a class="reference internal" href="#bitfield-references" id="id8">Bitfield references</a></li>
</ul>
</li>
<li><a class="reference internal" href="#named-types" id="id9">Named types</a></li>
<li><a class="reference internal" href="#global-functions" id="id10">Global functions</a></li>
<li><a class="reference internal" href="#recursive-table-assignment" id="id11">Recursive table assignment</a></li>
</ul>
</li>
<li><a class="reference internal" href="#dfhack-api" id="id12">DFHack API</a><ul>
<li><a class="reference internal" href="#native-utilities" id="id13">Native utilities</a><ul>
<li><a class="reference internal" href="#input-output" id="id14">Input & Output</a></li>
<li><a class="reference internal" href="#exception-handling" id="id15">Exception handling</a></li>
<li><a class="reference internal" href="#miscellaneous" id="id16">Miscellaneous</a></li>
<li><a class="reference internal" href="#locking-and-finalization" id="id17">Locking and finalization</a></li>
<li><a class="reference internal" href="#persistent-configuration-storage" id="id18">Persistent configuration storage</a></li>
<li><a class="reference internal" href="#material-info-lookup" id="id19">Material info lookup</a></li>
<li><a class="reference internal" href="#random-number-generation" id="id20">Random number generation</a></li>
</ul>
</li>
<li><a class="reference internal" href="#c-function-wrappers" id="id21">C++ function wrappers</a><ul>
<li><a class="reference internal" href="#gui-module" id="id22">Gui module</a></li>
<li><a class="reference internal" href="#job-module" id="id23">Job module</a></li>
<li><a class="reference internal" href="#units-module" id="id24">Units module</a></li>
<li><a class="reference internal" href="#items-module" id="id25">Items module</a></li>
<li><a class="reference internal" href="#maps-module" id="id26">Maps module</a></li>
<li><a class="reference internal" href="#burrows-module" id="id27">Burrows module</a></li>
<li><a class="reference internal" href="#buildings-module" id="id28">Buildings module</a></li>
<li><a class="reference internal" href="#constructions-module" id="id29">Constructions module</a></li>
<li><a class="reference internal" href="#screen-api" id="id30">Screen API</a></li>
<li><a class="reference internal" href="#internal-api" id="id31">Internal API</a></li>
</ul>
</li>
<li><a class="reference internal" href="#core-interpreter-context" id="id32">Core interpreter context</a><ul>
<li><a class="reference internal" href="#event-type" id="id33">Event type</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#lua-modules" id="id34">Lua Modules</a><ul>
<li><a class="reference internal" href="#global-environment" id="id35">Global environment</a></li>
<li><a class="reference internal" href="#utils" id="id36">utils</a></li>
<li><a class="reference internal" href="#dumper" id="id37">dumper</a></li>
<li><a class="reference internal" href="#class" id="id38">class</a></li>
</ul>
</li>
<li><a class="reference internal" href="#in-game-ui-library" id="id39">In-game UI Library</a><ul>
<li><a class="reference internal" href="#gui" id="id40">gui</a><ul>
<li><a class="reference internal" href="#misc" id="id41">Misc</a></li>
<li><a class="reference internal" href="#viewrect-class" id="id42">ViewRect class</a></li>
<li><a class="reference internal" href="#painter-class" id="id43">Painter class</a></li>
<li><a class="reference internal" href="#view-class" id="id44">View class</a></li>
<li><a class="reference internal" href="#screen-class" id="id45">Screen class</a></li>
<li><a class="reference internal" href="#framedscreen-class" id="id46">FramedScreen class</a></li>
</ul>
</li>
<li><a class="reference internal" href="#gui-widgets" id="id47">gui.widgets</a><ul>
<li><a class="reference internal" href="#widget-class" id="id48">Widget class</a></li>
<li><a class="reference internal" href="#panel-class" id="id49">Panel class</a></li>
<li><a class="reference internal" href="#pages-class" id="id50">Pages class</a></li>
<li><a class="reference internal" href="#editfield-class" id="id51">EditField class</a></li>
<li><a class="reference internal" href="#label-class" id="id52">Label class</a></li>
<li><a class="reference internal" href="#list-class" id="id53">List class</a></li>
<li><a class="reference internal" href="#filteredlist-class" id="id54">FilteredList class</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#plugins" id="id55">Plugins</a><ul>
<li><a class="reference internal" href="#burrows" id="id56">burrows</a></li>
<li><a class="reference internal" href="#sort" id="id57">sort</a></li>
<li><a class="reference internal" href="#eventful" id="id58">Eventful</a><ul>
<li><a class="reference internal" href="#list-of-events" id="id59">List of events</a></li>
<li><a class="reference internal" href="#events-from-eventmanager" id="id60">Events from EventManager</a></li>
<li><a class="reference internal" href="#functions" id="id61">Functions</a></li>
<li><a class="reference internal" href="#examples" id="id62">Examples</a></li>
</ul>
</li>
<li><a class="reference internal" href="#building-hacks" id="id63">Building-hacks</a><ul>
<li><a class="reference internal" href="#id1" id="id64">Functions</a></li>
<li><a class="reference internal" href="#id2" id="id65">Examples</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#scripts" id="id66">Scripts</a><ul>
<li><a class="reference internal" href="#save-init-script" id="id67">Save init script</a></li>
</ul>
</li>
</ul>
</div>
<p>The current version of DFHack has extensive support for
the Lua scripting language, providing access to:</p>
<ol class="arabic simple">
<li>Raw data structures used by the game.</li>
<li>Many C++ functions for high-level access to these
structures, and interaction with dfhack itself.</li>
<li>Some functions exported by C++ plugins.</li>
</ol>
<p>Lua code can be used both for writing scripts, which
are treated by DFHack command line prompt almost as
native C++ commands, and invoked by plugins written in c++.</p>
<p>This document describes native API available to Lua in detail.
It does not describe all of the utility functions
implemented by Lua files located in hack/lua/...</p>
<div class="section" id="df-data-structure-wrapper">
<h1><a class="toc-backref" href="#id3">DF data structure wrapper</a></h1>
<p>Data structures of the game are defined in XML files located in library/xml
(and online at <a class="reference external" href="http://github.com/DFHack/df-structures">http://github.com/DFHack/df-structures</a>), and automatically exported
to lua code as a tree of objects and functions under the <tt class="docutils literal">df</tt> global, which
also broadly maps to the <tt class="docutils literal">df</tt> namespace in the headers generated for C++.</p>
<p><strong>WARNING</strong>: The wrapper provides almost raw access to the memory
of the game, so mistakes in manipulating objects are as likely to
crash the game as equivalent plain C++ code would be. E.g. NULL
pointer access is safely detected, but dangling pointers aren't.</p>
<p>Objects managed by the wrapper can be broadly classified into the following groups:</p>
<ol class="arabic">
<li><p class="first">Typed object pointers (references).</p>
<p>References represent objects in DF memory with a known type.</p>
<p>In addition to fields and methods defined by the wrapped type,
every reference has some built-in properties and methods.</p>
</li>
<li><p class="first">Untyped pointers</p>
<p>Represented as lightuserdata.</p>
<p>In assignment to a pointer NULL can be represented either as
<tt class="docutils literal">nil</tt>, or a NULL lightuserdata; reading a NULL pointer field
returns <tt class="docutils literal">nil</tt>.</p>
</li>
<li><p class="first">Named types</p>
<p>Objects in the <tt class="docutils literal">df</tt> tree that represent identity of struct, class,
enum and bitfield types. They host nested named types, static
methods, builtin properties & methods, and, for enums and bitfields,
the bi-directional mapping between key names and values.</p>
</li>
<li><p class="first">The <tt class="docutils literal">global</tt> object</p>
<p><tt class="docutils literal">df.global</tt> corresponds to the <tt class="docutils literal"><span class="pre">df::global</span></tt> namespace, and
behaves as a mix between a named type and a reference, containing
both nested types and fields corresponding to global symbols.</p>
</li>
</ol>
<p>In addition to the <tt class="docutils literal">global</tt> object and top-level types the <tt class="docutils literal">df</tt>
global also contains a few global builtin utility functions.</p>
<div class="section" id="typed-object-references">
<h2><a class="toc-backref" href="#id4">Typed object references</a></h2>
<p>The underlying primitive lua object is userdata with a metatable.
Every structured field access produces a new userdata instance.</p>
<p>All typed objects have the following built-in features:</p>
<ul>
<li><p class="first"><tt class="docutils literal">ref1 == ref2</tt>, <tt class="docutils literal">tostring(ref)</tt></p>
<p>References implement equality by type & pointer value, and string conversion.</p>
</li>
<li><p class="first"><tt class="docutils literal">pairs(ref)</tt></p>
<p>Returns an iterator for the sequence of actual C++ field names
and values. Fields are enumerated in memory order. Methods and
lua wrapper properties are not included in the iteration.</p>
<p><strong>WARNING</strong>: a few of the data structures (like ui_look_list)
contain unions with pointers to different types with vtables.
Using pairs on such structs is an almost sure way to crash with
an access violation.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref._kind</tt></p>
<p>Returns one of: <tt class="docutils literal">primitive</tt>, <tt class="docutils literal">struct</tt>, <tt class="docutils literal">container</tt>,
or <tt class="docutils literal">bitfield</tt>, as appropriate for the referenced object.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref._type</tt></p>
<p>Returns the named type object or a string that represents
the referenced object type.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref:sizeof()</tt></p>
<p>Returns <em>size, address</em></p>
</li>
<li><p class="first"><tt class="docutils literal">ref:new()</tt></p>
<p>Allocates a new instance of the same type, and copies data
from the current object.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref:delete()</tt></p>
<p>Destroys the object with the C++ <tt class="docutils literal">delete</tt> operator.
If destructor is not available, returns <em>false</em>.</p>
<p><strong>WARNING</strong>: the lua reference object remains as a dangling
pointer, like a raw C++ pointer would.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref:assign(object)</tt></p>
<p>Assigns data from object to ref. Object must either be another
ref of a compatible type, or a lua table; in the latter case
special recursive assignment rules are applied.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">ref:_displace(index[,step])</span></tt></p>
<p>Returns a new reference with the pointer adjusted by index*step.
Step defaults to the natural object size.</p>
</li>
</ul>
<div class="section" id="primitive-references">
<h3><a class="toc-backref" href="#id5">Primitive references</a></h3>
<p>References of the <em>_kind</em> <tt class="docutils literal">'primitive'</tt> are used for objects
that don't fit any of the other reference types. Such
references can only appear as a value of a pointer field,
or as a result of calling the <tt class="docutils literal">_field()</tt> method.</p>
<p>They behave as structs with one field <tt class="docutils literal">value</tt> of the right type.</p>
<p>To make working with numeric buffers easier, they also allow
numeric indices. Note that other than excluding negative values
no bound checking is performed, since buffer length is not available.
Index 0 is equivalent to the <tt class="docutils literal">value</tt> field.</p>
</div>
<div class="section" id="struct-references">
<h3><a class="toc-backref" href="#id6">Struct references</a></h3>
<p>Struct references are used for class and struct objects.</p>
<p>They implement the following features:</p>
<ul>
<li><p class="first"><tt class="docutils literal">ref.field</tt>, <tt class="docutils literal">ref.field = value</tt></p>
<p>Valid fields of the structure may be accessed by subscript.</p>
<p>Primitive typed fields, i.e. numbers & strings, are converted
to/from matching lua values. The value of a pointer is a reference
to the target, or nil/NULL. Complex types are represented by
a reference to the field within the structure; unless recursive
lua table assignment is used, such fields can only be read.</p>
<p><strong>NOTE:</strong> In case of inheritance, <em>superclass</em> fields have precedence
over the subclass, but fields shadowed in this way can still
be accessed as <tt class="docutils literal"><span class="pre">ref['subclasstype.field']</span></tt>.
This shadowing order is necessary because vtable-based classes
are automatically exposed in their exact type, and the reverse
rule would make access to superclass fields unreliable.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref._field(field)</tt></p>
<p>Returns a reference to a valid field. That is, unlike regular
subscript, it returns a reference to the field within the structure
even for primitive typed fields and pointers.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">ref:vmethod(args...)</span></tt></p>
<p>Named virtual methods are also exposed, subject to the same
shadowing rules.</p>
</li>
<li><p class="first"><tt class="docutils literal">pairs(ref)</tt></p>
<p>Enumerates all real fields (but not methods) in memory
(= declaration) order.</p>
</li>
</ul>
</div>
<div class="section" id="container-references">
<h3><a class="toc-backref" href="#id7">Container references</a></h3>
<p>Containers represent vectors and arrays, possibly resizable.</p>
<p>A container field can associate an enum to the container
reference, which allows accessing elements using string keys
instead of numerical indices.</p>
<p>Implemented features:</p>
<ul>
<li><p class="first"><tt class="docutils literal">ref._enum</tt></p>
<p>If the container has an associated enum, returns the matching
named type object.</p>
</li>
<li><p class="first"><tt class="docutils literal">#ref</tt></p>
<p>Returns the <em>length</em> of the container.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref[index]</tt></p>
<p>Accesses the container element, using either a <em>0-based</em> numerical
index, or, if an enum is associated, a valid enum key string.</p>
<p>Accessing an invalid index is an error, but some container types
may return a default value, or auto-resize instead for convenience.
Currently this relaxed mode is implemented by df-flagarray aka BitArray.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref._field(index)</tt></p>
<p>Like with structs, returns a pointer to the array element, if possible.
Flag and bit arrays cannot return such pointer, so it fails with an error.</p>
</li>
<li><p class="first"><tt class="docutils literal">pairs(ref)</tt>, <tt class="docutils literal">ipairs(ref)</tt></p>
<p>If the container has no associated enum, both behave identically,
iterating over numerical indices in order. Otherwise, ipairs still
uses numbers, while pairs tries to substitute enum keys whenever
possible.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref:resize(new_size)</tt></p>
<p>Resizes the container if supported, or fails with an error.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref:insert(index,item)</tt></p>
<p>Inserts a new item at the specified index. To add at the end,
use <tt class="docutils literal">#ref</tt>, or just <tt class="docutils literal">'#'</tt> as index.</p>
</li>
<li><p class="first"><tt class="docutils literal">ref:erase(index)</tt></p>
<p>Removes the element at the given valid index.</p>
</li>
</ul>
</div>
<div class="section" id="bitfield-references">
<h3><a class="toc-backref" href="#id8">Bitfield references</a></h3>
<p>Bitfields behave like special fixed-size containers.
Consider them to be something in between structs and
fixed-size vectors.</p>
<p>The <tt class="docutils literal">_enum</tt> property points to the bitfield type.
Numerical indices correspond to the shift value,
and if a subfield occupies multiple bits, the
<tt class="docutils literal">ipairs</tt> order would have a gap.</p>
<p>Since currently there is no API to allocate a bitfield
object fully in GC-managed lua heap, consider using the
lua table assignment feature outlined below in order to
pass bitfield values to dfhack API functions that need
them, e.g. <tt class="docutils literal">matinfo:matches{metal=true}</tt>.</p>
</div>
</div>
<div class="section" id="named-types">
<h2><a class="toc-backref" href="#id9">Named types</a></h2>
<p>Named types are exposed in the <tt class="docutils literal">df</tt> tree with names identical
to the C++ version, except for the <tt class="docutils literal">::</tt> vs <tt class="docutils literal">.</tt> difference.</p>
<p>All types and the global object have the following features:</p>
<ul>
<li><p class="first"><tt class="docutils literal">type._kind</tt></p>
<p>Evaluates to one of <tt class="docutils literal"><span class="pre">struct-type</span></tt>, <tt class="docutils literal"><span class="pre">class-type</span></tt>, <tt class="docutils literal"><span class="pre">enum-type</span></tt>,
<tt class="docutils literal"><span class="pre">bitfield-type</span></tt> or <tt class="docutils literal">global</tt>.</p>
</li>
<li><p class="first"><tt class="docutils literal">type._identity</tt></p>
<p>Contains a lightuserdata pointing to the underlying
DFHack::type_instance object.</p>
</li>
</ul>
<p>Types excluding the global object also support:</p>
<ul>
<li><p class="first"><tt class="docutils literal">type:sizeof()</tt></p>
<p>Returns the size of an object of the type.</p>
</li>
<li><p class="first"><tt class="docutils literal">type:new()</tt></p>
<p>Creates a new instance of an object of the type.</p>
</li>
<li><p class="first"><tt class="docutils literal">type:is_instance(object)</tt></p>
<p>Returns true if object is same or subclass type, or a reference
to an object of same or subclass type. It is permissible to pass
nil, NULL or non-wrapper value as object; in this case the
method returns nil.</p>
</li>
</ul>
<p>In addition to this, enum and bitfield types contain a
bi-directional mapping between key strings and values, and
also map <tt class="docutils literal">_first_item</tt> and <tt class="docutils literal">_last_item</tt> to the min and
max values.</p>
<p>Struct and class types with instance-vector attribute in the
xml have a <tt class="docutils literal">type.find(key)</tt> function that wraps the find
method provided in C++.</p>
</div>
<div class="section" id="global-functions">
<h2><a class="toc-backref" href="#id10">Global functions</a></h2>
<p>The <tt class="docutils literal">df</tt> table itself contains the following functions and values:</p>
<ul>
<li><p class="first"><tt class="docutils literal">NULL</tt>, <tt class="docutils literal">df.NULL</tt></p>
<p>Contains the NULL lightuserdata.</p>
</li>
<li><p class="first"><tt class="docutils literal">df.isnull(obj)</tt></p>
<p>Evaluates to true if obj is nil or NULL; false otherwise.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">df.isvalid(obj[,allow_null])</span></tt></p>
<p>For supported objects returns one of <tt class="docutils literal">type</tt>, <tt class="docutils literal">voidptr</tt>, <tt class="docutils literal">ref</tt>.</p>
<p>If <em>allow_null</em> is true, and obj is nil or NULL, returns <tt class="docutils literal">null</tt>.</p>
<p>Otherwise returns <em>nil</em>.</p>
</li>
<li><p class="first"><tt class="docutils literal">df.sizeof(obj)</tt></p>
<p>For types and refs identical to <tt class="docutils literal">obj:sizeof()</tt>.
For lightuserdata returns <em>nil, address</em></p>
</li>
<li><p class="first"><tt class="docutils literal">df.new(obj)</tt>, <tt class="docutils literal">df.delete(obj)</tt>, <tt class="docutils literal">df.assign(obj, obj2)</tt></p>
<p>Equivalent to using the matching methods of obj.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">df._displace(obj,index[,step])</span></tt></p>
<p>For refs equivalent to the method, but also works with
lightuserdata (step is mandatory then).</p>
</li>
<li><p class="first"><tt class="docutils literal">df.is_instance(type,obj)</tt></p>
<p>Equivalent to the method, but also allows a reference as proxy for its type.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">df.new(ptype[,count])</span></tt></p>
<p>Allocate a new instance, or an array of built-in types.
The <tt class="docutils literal">ptype</tt> argument is a string from the following list:
<tt class="docutils literal">string</tt>, <tt class="docutils literal">int8_t</tt>, <tt class="docutils literal">uint8_t</tt>, <tt class="docutils literal">int16_t</tt>, <tt class="docutils literal">uint16_t</tt>,
<tt class="docutils literal">int32_t</tt>, <tt class="docutils literal">uint32_t</tt>, <tt class="docutils literal">int64_t</tt>, <tt class="docutils literal">uint64_t</tt>, <tt class="docutils literal">bool</tt>,
<tt class="docutils literal">float</tt>, <tt class="docutils literal">double</tt>. All of these except <tt class="docutils literal">string</tt> can be
used with the count argument to allocate an array.</p>
</li>
<li><p class="first"><tt class="docutils literal">df.reinterpret_cast(type,ptr)</tt></p>
<p>Converts ptr to a ref of specified type. The type may be anything
acceptable to <tt class="docutils literal">df.is_instance</tt>. Ptr may be <em>nil</em>, a ref,
a lightuserdata, or a number.</p>
<p>Returns <em>nil</em> if NULL, or a ref.</p>
</li>
</ul>
</div>
<div class="section" id="recursive-table-assignment">
<h2><a class="toc-backref" href="#id11">Recursive table assignment</a></h2>
<p>Recursive assignment is invoked when a lua table is assigned
to a C++ object or field, i.e. one of:</p>
<ul class="simple">
<li><tt class="docutils literal"><span class="pre">ref:assign{...}</span></tt></li>
<li><tt class="docutils literal">ref.field = <span class="pre">{...}</span></tt></li>
</ul>
<p>The general mode of operation is that all fields of the table
are assigned to the fields of the target structure, roughly
emulating the following code:</p>
<pre class="literal-block">
function rec_assign(ref,table)
for key,value in pairs(table) do
ref[key] = value
end
end
</pre>
<p>Since assigning a table to a field using = invokes the same
process, it is recursive.</p>
<p>There are however some variations to this process depending
on the type of the field being assigned to:</p>
<ol class="arabic">
<li><p class="first">If the table contains an <tt class="docutils literal">assign</tt> field, it is
applied first, using the <tt class="docutils literal">ref:assign(value)</tt> method.
It is never assigned as a usual field.</p>
</li>
<li><p class="first">When a table is assigned to a non-NULL pointer field
using the <tt class="docutils literal">ref.field = <span class="pre">{...}</span></tt> syntax, it is applied
to the target of the pointer instead.</p>
<p>If the pointer is NULL, the table is checked for a <tt class="docutils literal">new</tt> field:</p>
<ol class="loweralpha simple">
<li>If it is <em>nil</em> or <em>false</em>, assignment fails with an error.</li>
<li>If it is <em>true</em>, the pointer is initialized with a newly
allocated object of the declared target type of the pointer.</li>
<li>Otherwise, <tt class="docutils literal">table.new</tt> must be a named type, or an
object of a type compatible with the pointer. The pointer
is initialized with the result of calling <tt class="docutils literal">table.new:new()</tt>.</li>
</ol>
<p>After this auto-vivification process, assignment proceeds
as if the pointer wasn't NULL.</p>
<p>Obviously, the <tt class="docutils literal">new</tt> field inside the table is always skipped
during the actual per-field assignment processing.</p>
</li>
<li><p class="first">If the target of the assignment is a container, a separate
rule set is used:</p>
<ol class="loweralpha">
<li><p class="first">If the table contains neither <tt class="docutils literal">assign</tt> nor <tt class="docutils literal">resize</tt>
fields, it is interpreted as an ordinary <em>1-based</em> lua
array. The container is resized to the #-size of the
table, and elements are assigned in numeric order:</p>
<pre class="literal-block">
ref:resize(#table);
for i=1,#table do ref[i-1] = table[i] end
</pre>
</li>
<li><p class="first">Otherwise, <tt class="docutils literal">resize</tt> must be <em>true</em>, <em>false</em>, or
an explicit number. If it is not false, the container
is resized. After that the usual struct-like 'pairs'
assignment is performed.</p>
<p>In case <tt class="docutils literal">resize</tt> is <em>true</em>, the size is computed
by scanning the table for the largest numeric key.</p>
</li>
</ol>
<p>This means that in order to reassign only one element of
a container using this system, it is necessary to use:</p>
<pre class="literal-block">
{ resize=false, [idx]=value }
</pre>
</li>
</ol>
<p>Since nil inside a table is indistinguishable from missing key,
it is necessary to use <tt class="docutils literal">df.NULL</tt> as a null pointer value.</p>
<p>This system is intended as a way to define a nested object
tree using pure lua data structures, and then materialize it in
C++ memory in one go. Note that if pointer auto-vivification
is used, an error in the middle of the recursive walk would
not destroy any objects allocated in this way, so the user
should be prepared to catch the error and do the necessary
cleanup.</p>
</div>
</div>
<div class="section" id="dfhack-api">
<h1><a class="toc-backref" href="#id12">DFHack API</a></h1>
<p>DFHack utility functions are placed in the <tt class="docutils literal">dfhack</tt> global tree.</p>
<div class="section" id="native-utilities">
<h2><a class="toc-backref" href="#id13">Native utilities</a></h2>
<div class="section" id="input-output">
<h3><a class="toc-backref" href="#id14">Input & Output</a></h3>
<ul>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.print(args...)</span></tt></p>
<p>Output tab-separated args as standard lua print would do,
but without a newline.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">print(args...)</span></tt>, <tt class="docutils literal"><span class="pre">dfhack.println(args...)</span></tt></p>
<p>A replacement of the standard library print function that
works with DFHack output infrastructure.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.printerr(args...)</span></tt></p>
<p>Same as println; intended for errors. Uses red color and logs to stderr.log.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.color([color])</span></tt></p>
<p>Sets the current output color. If color is <em>nil</em> or <em>-1</em>, resets to default.
Returns the previous color value.</p>
</li>
<li><p class="first"><tt class="docutils literal">dfhack.is_interactive()</tt></p>
<p>Checks if the thread can access the interactive console and returns <em>true</em> or <em>false</em>.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.lineedit([prompt[,history_filename]])</span></tt></p>
<p>If the thread owns the interactive console, shows a prompt
and returns the entered string. Otherwise returns <em>nil, error</em>.</p>
<p>Depending on the context, this function may actually yield the
running coroutine and let the C++ code release the core suspend
lock. Using an explicit <tt class="docutils literal">dfhack.with_suspend</tt> will prevent
this, forcing the function to block on input with lock held.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.interpreter([prompt[,history_filename[,env]]])</span></tt></p>
<p>Starts an interactive lua interpreter, using the specified prompt
string, global environment and command-line history file.</p>
<p>If the interactive console is not accessible, returns <em>nil, error</em>.</p>
</li>
</ul>
</div>
<div class="section" id="exception-handling">
<h3><a class="toc-backref" href="#id15">Exception handling</a></h3>
<ul>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.error(msg[,level[,verbose]])</span></tt></p>
<p>Throws a dfhack exception object with location and stack trace.
The verbose parameter controls whether the trace is printed by default.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">qerror(msg[,level])</span></tt></p>
<p>Calls <tt class="docutils literal">dfhack.error()</tt> with <tt class="docutils literal">verbose</tt> being <em>false</em>. Intended to
be used for user-caused errors in scripts, where stack traces are not
desirable.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.pcall(f[,args...])</span></tt></p>
<p>Invokes f via xpcall, using an error function that attaches
a stack trace to the error. The same function is used by SafeCall
in C++, and dfhack.safecall.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">safecall(f[,args...])</span></tt>, <tt class="docutils literal"><span class="pre">dfhack.safecall(f[,args...])</span></tt></p>
<p>Just like pcall, but also prints the error using printerr before
returning. Intended as a convenience function.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.saferesume(coroutine[,args...])</span></tt></p>
<p>Compares to coroutine.resume like dfhack.safecall vs pcall.</p>
</li>
<li><p class="first"><tt class="docutils literal">dfhack.exception</tt></p>
<p>Metatable of error objects used by dfhack. The objects have the
following properties:</p>
<dl class="docutils">
<dt><tt class="docutils literal">err.where</tt></dt>
<dd><p class="first last">The location prefix string, or <em>nil</em>.</p>
</dd>
<dt><tt class="docutils literal">err.message</tt></dt>
<dd><p class="first last">The base message string.</p>
</dd>
<dt><tt class="docutils literal">err.stacktrace</tt></dt>
<dd><p class="first last">The stack trace string, or <em>nil</em>.</p>
</dd>
<dt><tt class="docutils literal">err.cause</tt></dt>
<dd><p class="first last">A different exception object, or <em>nil</em>.</p>
</dd>
<dt><tt class="docutils literal">err.thread</tt></dt>
<dd><p class="first last">The coroutine that has thrown the exception.</p>
</dd>
<dt><tt class="docutils literal">err.verbose</tt></dt>
<dd><p class="first last">Boolean, or <em>nil</em>; specifies if where and stacktrace should be printed.</p>
</dd>
<dt><tt class="docutils literal">tostring(err)</tt>, or <tt class="docutils literal"><span class="pre">err:tostring([verbose])</span></tt></dt>
<dd><p class="first last">Converts the exception to string.</p>
</dd>
</dl>
</li>
<li><p class="first"><tt class="docutils literal">dfhack.exception.verbose</tt></p>
<p>The default value of the <tt class="docutils literal">verbose</tt> argument of <tt class="docutils literal">err:tostring()</tt>.</p>
</li>
</ul>
</div>
<div class="section" id="miscellaneous">
<h3><a class="toc-backref" href="#id16">Miscellaneous</a></h3>
<ul>
<li><p class="first"><tt class="docutils literal">dfhack.VERSION</tt></p>
<p>DFHack version string constant.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.curry(func,args...)</span></tt>, or <tt class="docutils literal"><span class="pre">curry(func,args...)</span></tt></p>
<p>Returns a closure that invokes the function with args combined
both from the curry call and the closure call itself. I.e.
<tt class="docutils literal"><span class="pre">curry(func,a,b)(c,d)</span></tt> equals <tt class="docutils literal">func(a,b,c,d)</tt>.</p>
</li>
</ul>
</div>
<div class="section" id="locking-and-finalization">
<h3><a class="toc-backref" href="#id17">Locking and finalization</a></h3>
<ul>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.with_suspend(f[,args...])</span></tt></p>
<p>Calls <tt class="docutils literal">f</tt> with arguments after grabbing the DF core suspend lock.
Suspending is necessary for accessing a consistent state of DF memory.</p>
<p>Returned values and errors are propagated through after releasing
the lock. It is safe to nest suspends.</p>
<p>Every thread is allowed only one suspend per DF frame, so it is best
to group operations together in one big critical section. A plugin
can choose to run all lua code inside a C++-side suspend lock.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.call_with_finalizer(num_cleanup_args,always,cleanup_fn[,cleanup_args...],fn[,args...])</span></tt></p>
<p>Invokes <tt class="docutils literal">fn</tt> with <tt class="docutils literal">args</tt>, and after it returns or throws an
error calls <tt class="docutils literal">cleanup_fn</tt> with <tt class="docutils literal">cleanup_args</tt>. Any return values from
<tt class="docutils literal">fn</tt> are propagated, and errors are re-thrown.</p>
<p>The <tt class="docutils literal">num_cleanup_args</tt> integer specifies the number of <tt class="docutils literal">cleanup_args</tt>,
and the <tt class="docutils literal">always</tt> boolean specifies if cleanup should be called in any case,
or only in case of an error.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.with_finalize(cleanup_fn,fn[,args...])</span></tt></p>
<p>Calls <tt class="docutils literal">fn</tt> with arguments, then finalizes with <tt class="docutils literal">cleanup_fn</tt>.
Implemented using <tt class="docutils literal"><span class="pre">call_with_finalizer(0,true,...)</span></tt>.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.with_onerror(cleanup_fn,fn[,args...])</span></tt></p>
<p>Calls <tt class="docutils literal">fn</tt> with arguments, then finalizes with <tt class="docutils literal">cleanup_fn</tt> on any thrown error.
Implemented using <tt class="docutils literal"><span class="pre">call_with_finalizer(0,false,...)</span></tt>.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.with_temp_object(obj,fn[,args...])</span></tt></p>
<p>Calls <tt class="docutils literal"><span class="pre">fn(obj,args...)</span></tt>, then finalizes with <tt class="docutils literal">obj:delete()</tt>.</p>
</li>
</ul>
</div>
<div class="section" id="persistent-configuration-storage">
<h3><a class="toc-backref" href="#id18">Persistent configuration storage</a></h3>
<p>This api is intended for storing configuration options in the world itself.
It probably should be restricted to data that is world-dependent.</p>
<p>Entries are identified by a string <tt class="docutils literal">key</tt>, but it is also possible to manage
multiple entries with the same key; their identity is determined by <tt class="docutils literal">entry_id</tt>.
Every entry has a mutable string <tt class="docutils literal">value</tt>, and an array of 7 mutable <tt class="docutils literal">ints</tt>.</p>
<ul>
<li><p class="first"><tt class="docutils literal">dfhack.persistent.get(key)</tt>, <tt class="docutils literal">entry:get()</tt></p>
<p>Retrieves a persistent config record with the given string key,
or refreshes an already retrieved entry. If there are multiple
entries with the same key, it is undefined which one is retrieved
by the first version of the call.</p>
<p>Returns entry, or <em>nil</em> if not found.</p>
</li>
<li><p class="first"><tt class="docutils literal">dfhack.persistent.delete(key)</tt>, <tt class="docutils literal">entry:delete()</tt></p>
<p>Removes an existing entry. Returns <em>true</em> if succeeded.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.persistent.get_all(key[,match_prefix])</span></tt></p>
<p>Retrieves all entries with the same key, or starting with key..'/'.
Calling <tt class="docutils literal"><span class="pre">get_all('',true)</span></tt> will match all entries.</p>
<p>If none found, returns nil; otherwise returns an array of entries.</p>
</li>
<li><p class="first"><tt class="docutils literal"><span class="pre">dfhack.persistent.save({key=str1,</span> <span class="pre">...}[,new])</span></tt>, <tt class="docutils literal"><span class="pre">entry:save([new])</span></tt></p>
<p>Saves changes in an entry, or creates a new one. Passing true as
new forces creation of a new entry even if one already exists;
otherwise the existing one is simply updated.
Returns <em>entry, did_create_new</em></p>
</li>
</ul>
<p>Since the data is hidden in data structures owned by the DF world,
and automatically stored in the save game, these save and retrieval
functions can just copy values in memory without doing any actual I/O.
However, currently every entry has a 180+-byte dead-weight overhead.</p>
<p>It is also possible to associate one bit per map tile with an entry,
using these two methods:</p>
<ul>
<li><p class="first"><tt class="docutils literal">entry:getTilemask(block[, create])</tt></p>
<p>Retrieves the tile bitmask associated with this entry in the given map
block. If <tt class="docutils literal">create</tt> is <em>true</em>, an empty mask is created if none exists;
otherwise the function returns <em>nil</em>, which must be assumed to be the same
as an all-zero mask.</p>
</li>
<li><p class="first"><tt class="docutils literal">entry:deleteTilemask(block)</tt></p>
<p>Deletes the associated tile mask from the given map block.</p>